All packets received and the trip time is short: Your device and PC are over same network, and network is stable.

Some packets lost or the trip time is long: Though your device and PC are over same network, the network is unstable. In this case, the connection mode is probably Remote Connection Mode. Try to connect again.

All packets lost: Your device and PC are not in the same network. Reboot the router or ask for help from network admin.

It means the network connection works fine, your device and PC are connected to the same network. The connection mode should be LAN Connection Mode.Otherwise there are some problem with the network connection.

Try these methods to fix:

Check whether the firewall of your device blocks AirDroid service

Restart AirDroid if your device can access the network.

Connect to Wi-Fi again if your device cannot access the network

3. If all previous steps fail, and if you use any plugin to block javascript (or other scripts)on your browser, tune the plugin or turn it off.